VPN: An ErrorPresenter class to consolidate showing of error alerts

WireGuard/WireGuard.xcodeproj/project.pbxproj

@@ -28,6 +28,7 @@
 		6F7774EA217229DB006A79B3 /* IPAddressRange.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6F7774E9217229DB006A79B3 /* IPAddressRange.swift */; };
 		6F7774EF21722D97006A79B3 /* TunnelsManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6F7774EE21722D97006A79B3 /* TunnelsManager.swift */; };
 		6F7774F321774263006A79B3 /* TunnelEditTableViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6F7774F221774263006A79B3 /* TunnelEditTableViewController.swift */; };
+		6F919EC3218A2AE90023B400 /* ErrorPresenter.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6F919EC2218A2AE90023B400 /* ErrorPresenter.swift */; };
 		6FDEF7E421846C1A00D8FBF6 /* libwg-go.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 6FDEF7E321846C1A00D8FBF6 /* libwg-go.a */; };
 		6FDEF7E62185EFB200D8FBF6 /* QRScanViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6FDEF7E52185EFAF00D8FBF6 /* QRScanViewController.swift */; };
 		6FDEF7FB21863B6100D8FBF6 /* unzip.c in Sources */ = {isa = PBXBuildFile; fileRef = 6FDEF7F621863B6100D8FBF6 /* unzip.c */; };
@@ -97,7 +98,8 @@
 		6F7774E9217229DB006A79B3 /* IPAddressRange.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IPAddressRange.swift; sourceTree = "<group>"; };
 		6F7774EE21722D97006A79B3 /* TunnelsManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TunnelsManager.swift; sourceTree = "<group>"; };
 		6F7774F221774263006A79B3 /* TunnelEditTableViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TunnelEditTableViewController.swift; sourceTree = "<group>"; };
-		6FDEF7E321846C1A00D8FBF6 /* libwg-go.a */ = {isa = PBXFileReference; explicitFileType = "archive.ar"; path = "libwg-go.a"; sourceTree = BUILT_PRODUCTS_DIR; };
+		6F919EC2218A2AE90023B400 /* ErrorPresenter.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ErrorPresenter.swift; sourceTree = "<group>"; };
+		6FDEF7E321846C1A00D8FBF6 /* libwg-go.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; path = "libwg-go.a"; sourceTree = BUILT_PRODUCTS_DIR; };
 		6FDEF7E52185EFAF00D8FBF6 /* QRScanViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = QRScanViewController.swift; sourceTree = "<group>"; };
 		6FDEF7F621863B6100D8FBF6 /* unzip.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = unzip.c; sourceTree = "<group>"; };
 		6FDEF7F721863B6100D8FBF6 /* zip.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = zip.c; sourceTree = "<group>"; };
@@ -194,6 +196,7 @@
 				6F7774F221774263006A79B3 /* TunnelEditTableViewController.swift */,
 				6F628C40217F47DB003482A3 /* TunnelDetailTableViewController.swift */,
 				6FDEF805218725D200D8FBF6 /* SettingsTableViewController.swift */,
+				6F919EC2218A2AE90023B400 /* ErrorPresenter.swift */,
 			);
 			path = iOS;
 			sourceTree = "<group>";
@@ -473,6 +476,7 @@
 				6FDEF7FC21863B6100D8FBF6 /* zip.c in Sources */,
 				6F628C3F217F3413003482A3 /* DNSServer.swift in Sources */,
 				6F628C3D217F09E9003482A3 /* TunnelViewModel.swift in Sources */,
+				6F919EC3218A2AE90023B400 /* ErrorPresenter.swift in Sources */,
 				6FDEF8082187442100D8FBF6 /* WgQuickConfigFileWriter.swift in Sources */,
 				6F7774EA217229DB006A79B3 /* IPAddressRange.swift in Sources */,
 				6F7774E82172020C006A79B3 /* Configuration.swift in Sources */,

WireGuard/WireGuard/UI/iOS/ErrorPresenter.swift

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018 WireGuard LLC. All Rights Reserved.
+
+import UIKit
+import os.log
+
+class ErrorPresenter {
+    static func errorMessage(for error: Error) -> (String, String)? {
+        switch (error) {
+        case TunnelManagementError.tunnelAlreadyExistsWithThatName:
+            return ("Name already in use", "A tunnel with that name already exists. Please pick a different name.")
+        case TunnelManagementError.vpnSystemErrorOnAddTunnel:
+            return ("Could not create tunnel", "Internal error")
+        case TunnelManagementError.vpnSystemErrorOnModifyTunnel:
+            return ("Could not modify tunnel", "Internal error")
+        case TunnelManagementError.vpnSystemErrorOnRemoveTunnel:
+            return ("Could not remove tunnel", "Internal error")
+        default:
+            os_log("ErrorPresenter: Error not presented: %{public}@", log: OSLog.default, type: .error, "\(error)")
+            return nil
+        }
+    }
+
+    static func showErrorAlert(error: Error, from sourceVC: UIViewController?, onDismissal: (() -> Void)? = nil) {
+        guard let sourceVC = sourceVC else { return }
+        guard let (title, message) = ErrorPresenter.errorMessage(for: error) else { return }
+        let okAction = UIAlertAction(title: "Ok", style: .default) { (_) in
+            onDismissal?()
+        }
+        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
+        alert.addAction(okAction)
+
+        sourceVC.present(alert, animated: true)
+    }
+
+    static func showErrorAlert(title: String, message: String, from sourceVC: UIViewController?, onDismissal: (() -> Void)? = nil) {
+        guard let sourceVC = sourceVC else { return }
+        let okAction = UIAlertAction(title: "Ok", style: .default) { (_) in
+            onDismissal?()
+        }
+        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
+        alert.addAction(okAction)
+
+        sourceVC.present(alert, animated: true)
+    }
+}